assume cs:code
code segment
begin:mov ah,1
      mov al,2
      int 7ch
      call delay

      mov ah,2
      mov al,1
      int 7ch
      call delay

      mov ah,3
      int 7ch
      call delay

      mov ah,0
      int 7ch
      call delay

      mov ax,4c00h
      int 21h

delay:push cx
      mov cx,30h
  sp0:push cx
      mov cx,0ffffh
  sp1:loop sp1
      pop cx
      loop sp0
      pop cx
      ret
code ends
end begin
